Method of making fiber board



Aug. 6, 1929. o. MANTIUS 1,723,051

METHOD OF MAKING FIBER BOARD Filed March 16, 1928 2 Sheet-Sheet 1 INVENTOR.

ATT NEYS.

1929. o. MANTIUS 1,723,051

METHOD OF MAKING FIBER BOARD Filed March 16, 1928 2 Sheets-Sheet 2 11v VE/VZOR. 0/20 Man/m5 A T R/VEYS.

Patented Aug 6, 1929.

UNITED STATES PATENT OFFICE.

OTTO IANTIUS, 0] NEW YORK, N. Y.

IETHOD OI MAKING FIBER BOARD.

Application fled March 16, 1988. Serial No. 282,223.

4 form the pulp into a sheet. Pulp, as operated upon in this manner, contains about ninety per cent of water and it is to remove this water and form the pulp into sheets that it is acted upon by rolls or otherwise as stated. The common practice is to pass the pulp between a succession of coacting rolls, that is to say, the pulp after passing between one pair of coacting rollstravels for a distance without pressure and thereupon passes between a second set of coacting rolls. This operation is repeated, so that the pulp is successively passed between coactin pairs of rollers positioned at appreciable distances apart. The purpose of rolling the pulp as stated is to free the pulp from its water content.

During the operation of the pulp by a machine such as stated, the passing of the pulp between any particular set of rolls serves to squeeze out an appreciable portion of the water by highly compressing the pulp. I have noted, however, that as soon as the pulp passes from any particular set of rolls, its spongy nature causes it to immediately expand in thickness so that it acts after the manner of a sponge to again suck up a considerable amount of water before it is acted upon by the next set of rolls which are meanw ile squeezing out water from a forward portion of the pulp and feeding it to a following portion which is meanwhile expanding and sucking up the water. This operation occurs between each pair of rolls and materially lowers the elficienc of the machine for the reason that the pu p is not subjected to successive drying, but as a matter of fact is dried. to a certain extent, thereupon wet I again, then dried to a further extent, then wet again, etc., as it passes through successive rolling operations as stated. As a result, the prior machines of the character which I have referred to, and which constitute the standard apparatus of the prior art, are made quite heavy and embody a relatively large number of rolls, 1n order to obtain a product which will be commercially satisfactory.

My discoveries along the lines stated have convlnced me that the only satisfactory method of forming sheet fiber board from pulp in a continuous manner is to effect the drying of the pulp in a continuous manner. That s to say, to so act upon the pulp that it 1s sub ected to a continuousl increasm pressure wlthout cessation in t e application pf pressure.

This constitutes the broad concept of the present lnvention embodying a method of forming a relatively dry web from paper pulp wluch conslsts in moving the pulp continuously along a predetermined path and subectmgit during such passage to constantly moi-easing pressure which has the effect of progressively removin the water from the pulp and simultaneous y forming such pulp into a continuous web or sheet suitable for the final drying operation.

In practically carryin out the present invention, I find it desirab e to manipulate the is acted upon with increased pressures for a,

predetermined ortion of its travel in order to reduce the pu p ribbon to the desired thickness and after this has been accomplished, the web thus formed is maintained for a further period of its travel at such predetermined thickness in order that the web may be set at such thickness, so that when it is delivered from the last mentioned operation, it will not have an appreciable tendency to expand, but will retain substantially the thickness which has been fixed in the manner specified.

As a further step in the method of this invention, I remove the water which is squeezed out from the pulp in such manner that it will not have a detrimental further wetting effect upon the pulp that is being fed to the drying and forming operations stated.

Features of the invention, other than those adverted to, will be apparent from the hereinafter detailed description and claims, when read in conjunction with the accompanying drawin s.

. The lnvention may be practically carried out with various forms of apparatus, but an apparatus which has been found highly satisfactory is shown in the accompanying drawings. This apparatus is to be understood, however, as illustrative, only. and not as de fining the limits of the invention.

Figure 1 is a diagrammatic view of apparatus for carrying out the present invention, portions of the frame of the apparatus being shown in phantom, while other portions are shown in central section. All details have been omitted in this showing in the interests of clearness.

Fi re 2 is an enlarged vertical section showing the pressure applying rollers and the means whereby they are supported in coacting relation.

Figure 3 is a plan view of the lower set of rolls shown in Figure 2.

The machine shown in the drawings embodies a suitable frame. The frame is illus trated as embodying castings 1 and 2 connected together by side plates 3, one of which is positioned at each side of the machine and is rigidly bolted to the castings 1 and 2. The castings 1 and 2 are also duplicated at opposite sides of the machine, so that these parts when firmly bolted together constitute collectively the rigid frame of the apparatus.

Extending transversely of the machine and rigidly bolted at its opposite ends to the side plates 3 is a bed 4 preferably in the form of a casting suitably ribbed to impart strength thereto, but cored out so that it will not be excessively heavy.

Positioned in spaced relation above the bed 4 is what may be termed a cross head 5. This cross head extends transversely of the machine and is of the same general form as the bed 4 although inverted with respect thereto.

This cross head normally seats on the upper edges of the side plates 3 and is held to this seat by a number of springs 6 which embrace threaded posts 7 as shown. These posts are anchored at their lower ends in the side plates 3 and project upwardly in parallel vertical relation to one another. One spring 6 is coiled about each post and a nut 8 cooperates with the upper threaded end of each post in order that the springs may be placed under the desired tension suflicient to hold the cross head seated upon the upper edges of the side plates 3 while permitting of an upward yielding movement of the cross head in the event that the rollers which are associated therewith, as

hereinafter more fully described, engage some non-yielding foreign substance which may be found in the pulp on which they are adapted to operate. The normal position of the cross head is that wherein it rests upon the upper edges of the side plates 3 and this position may be regulated by introducing shims between the upper edges of the side plate and the cross head for reasons hereinafter more fully explained.

Mounted on the under face of the cross head 5 and on the upper face of the bed 4 are a plurality of rollers which may be secured to these parts in any suitable manner, but may conveniently be mounted as shown in Figs. 2 and 3. In these figures, 9 and 10 designate castings suitably reinforced and provided with holes 11 through which screws or bolts may be passed to secure the castings to the bed and cross head.

Each casting is formed to provide bearings for a number of rollers mounted in the casting in staggered relation to one another as shown in Fig. 3. That is to say, the rollers 12 are positioned in staggered relation to the rollers 14, i. e., the axes of the rollers 12 lie midway between the axes of the rollers 14, as viewed in Figs. 3 and 2. The rollers 12 and 14 are similarly disposed in the holder 9. The rollers 12 and 14 are the same as the rollers 12 and 14 in structure and are disposed in substantially the same manner except that their axes are mounted in slightly different relation presently to be explained and the same holds true of the relationship between the rollers 12 and 14 as compared with the rollers 12 and 14.

In a machine such as shown in Fig. 1, several holders of the character described are employed. That is to say, for example, six of such holders are mounted side by side on the bed 4 as shown in Fig. 3 and are firmly secured to the bed in such manner that the axes of the respective rollers will extend in a direction transversely of the machine. A like number of holders 10 are secured to the under face of the cross head 5, so that the upper face of the cross head will also carry a large number of rollers positioned in staggered relation on these respective parts, but with the corresponding rollers of both parts in juxtaposed relation to one another. Thus each roller 14 will be directly below its corresponding roller 14 and each roller 12 will be similarly disposed with respect to its corresponding roller 12. It will be noted that the rollers 12 and 14 and 12 and 14 are so mounted on their respective holders that they are of progressively decreasing distance apart in a direction from left to right in Figures 1 and 2. This will be apparent from the latter figure, wherein 15 designates a plane in which the axes of therollers 12 and 14" are included while 16 designates the plane in whichthe axes of the rollers 12 and 14 are included.

It will be noted that these planes converge to the right in this figure. Attention, howwhich I have descri 1,-rsa,ou

closer to one another as far as the line 20. Beyond this line are located the rollers 12, 14 and I2, 14'. which are spaced equal distances apart in a vertical direction.

The u per and lower roll sets which I have describe as mounted on the be% and cross head of the machine are spaced a art predetermined distances and betweenthempulp is adapted to be carried on endless conveyor belts which travel between the rolls. These belts which are designated 21 and 22 are preferably slat conveyors. They ma be conveniently formed of steel slats positioned edge to edge and extending transversely of the ma chine and mounted in this relation upon endless conveyor chainswhich serve to hold them in the desired relation and impart movement thereto.

The chains of the upper conveyor 21 are passed about sprockets 23 carried by the frame of the machine, while the chains of the lower conveyor are passed about sprockets 24 similarly mounted, as best shown in Fig. 1. These sprockets are driven through belts or chains 25 from any suitable source of power connected to shafts 26 and 27 so that the upper and lower conveyors are caused to continuously travel as shown.

Because of the pronounced l iquid condition of the pulp to be operated upon, I find it desirable to associate with the conveyors feed aprons. These feed aprons are in eifect endless conveyors. They are designated in the drawings by the reference characters 28 4 and 29 and are preferably wire mesh aprons. As shown in Figure 1, they are led about appropriate directional and tensioning rolls and pass between the operative reaches of the upper and lower conveyors 21 and 22. The purpose of these mesh aprons is to carry the pulp into cooperatively relation with the conveyors 21 and 22 in order that the pulp may be fed to the pressure zone and to thereafter remove the finlshed sheet from,the zone of pressure and feed it to an a propriate discharge table or out of the mac me.

In practically o crating the apparatus ed, the fiber pulp after having been suitably collected on a vacuum suction feeder, or otherwise, and thereby formed into a ribbon of from one to two inches thick is fed down a table 30 or in any other suitable manner to the lower apron 29 and is immediately carried by this apron into cooperative relation with the upper apron 28.

Thereafter these two aprons conjointly serve to move the pulp ribbon in the direction of the pressure rolls and thus carry it between the lower reach of the upper conveyor 21 andthe u per reach of the lower conveyor 22. This r1 bon of pulp generally con't'aips about ninety per cent of water and the aprons 28 and 29 are thus well suited to handle the pulp in this wet, semisolid condition.

As the pulp is carried by the upper and lower slat conveyors in a direction to the right in Fig. 1, it is gradually compressed and the water therein 1s gradually ueezed out so that by the time the pul reac es the first of the pressure rolls, it has een freed of some of its water content and in this condi? tion it passes into the tapering mouth between the pressure roll sets. The slats of the conveyors are substantially rigid and are sufiiciently wide to brid e over adjacent rolls of these sets. As a resuit the continued passage of the pulp into thewconstricted zone of pressure brings about theapplication of a constantly increasing amount of pressure which is not relieved, but in fact constantly increases from the time the pulp enters the pressure zone between the rollers until the time that it reaches the the line 20 in Figure 2.

By this time, the pulp has been subjected to a steady increase in pressure. As it continues beyond the line 20 in Fig. 2, the pressure is maintained substantially constant until it passes beyond the last rollers 14' and s the pressure constantly increases as the ulp moves alon the water is squeezed out o the pulp in su bstantially a constant stream and the pulp becomes dryer and dryer as it approaches the end of the pressure zone. The water thus squeezed from the pulp is drained through the small cracks between the slats of the conveyors. From the lower conveyor it will drop by gravity while from the upper conveyor, the water is removed by a suitable suction pump actin through a suction pipe 31. It will be note from the drawings that the web travels in an upwardly inclined direction so that the water squeezed point designated by out between the slats of the upper conveyor will flow down to the pipe 31.

I wish to particularly stress the fact that when the parts are .associated as described, the pressure rolls so act upon the slats of the conveyor that oncethey have entered between the upper and lower pressure rolls, the pressure is never relieved from these slats until the time they leave the pressure zone and pass from between said rollers.

On the contrary, the pressure is constantly increased without diminution at any point until theline 20 is reached, beyond which the pressure is maintained constant until the slats leave the last rolls in the pressure zone. Thus the structure shown not only serves to exertthe purpose of forming the pulp into a solid sheet and gradually decreasing such sheet to the predetermined thickness, this thickness being maintained during the latter part of the pressure zone in order to produce a fixed set in the finished product.

After leaving the pressure zone, the moist a sheet or web is led by the lower apron out of the present invention, it will be apparent that the disadvantages of prior practice to which I have referred are wholly eliminated by the method of this invention. The formation of the sheet is efficiently accomplished and a uniform product is produced through the employment of relatively simple mechanism. I

sists in feeding pulp along a predetermined lave not considered it necessary to show all of this mechanism in detail as this invention is drawn to the method while the apparatus forms the subject matter of a companion application Serial No. 262,224, filed March 16, 1928. It may be stated in passing, however, that while the taper of the pressure mouth is substantially fixed in the apparatus as shown,

the thickness of the finished sheet may be controlled by introducing shims between the cross head and-the upper edges of the side plates 3.

The purpose of the springs 8 is to permit the cross head to yield in the event that hard extraneous substances are entrained and carried along by the pulp into the pressure zone.

- If an unyielding arrangement were employed, breakage of 'the apparatus might result, but with the arrangement as shown, the parts will yield and permit the passage of the extraneous matter without damage to the apparatus.

The apparatus which I have illustrated for carrying out this method embodies mechanism for causing pulp to travel between and with substantially plane hard surfaces positioned' in converging relation to one another and adapted to simultaneously travel in a direction of their convergence, so that by this apparatus I am able to mechanically carry out the method hereinbcfore defined by the slat conveyors as shown. This apparatus is highly eflicient in carrying out the method of this invention, but I wish it understod that the method is not limited to this particular apparatus, but is rather to be construed as fully commensurate with the appended claims.

Having thus fully described the invention,

what I claim as new and desire to secure by Letters Patent is:

1. The herein described method of making along such path a substantially constant pres- I sure in order to set said sheet at the desired thickness.

2. The herein described method which con.-

path, subjecting said pulp during its movement along a portion of its complete travel to constantly uniformly increasing pressure to squeeze out excess water from the pulp and term the pulp into a sheet, and applying to the Dfll, for a further portion of its travel a constant pressure substantially equal to the maximum pressure produced in forming the sheet in order to set the thickness of such sheet.

3. The herein described method which consists in causing pulp in a loose, wet condition to travel along a predetermined path, subjectmg pulp during the )ortion of such travel to constantly uniform y increasing pressure, starting at a substantially zero pressure and finishing with a predetermined maximum pressure, and maintaining such maximum pressure for an appreciable distance in the travel of the materialwhereby the loose pul I is partially dried and formed into a sheet an the thickness of the sheet thereupon set.

4. The herein described method which consists in causing substantially plane hard surfaces positioned in converging relation to one another to simultaneously travel in the direction of their convergence, and introducing pulp between the said surfaces whereby the movement of said surfaces will cause the pulp to be subjected to constantly uniformly increasing pressure which will free the pulp of excess water and form the pulp into a solid sheet, and thereafter causing the sheet thus formed to travel for a distance between hard, unyielding surfaces spaced a uniform distance apart in order to set the sheet thus formed.

In testimony whereof I have signed the foregoing specification. 

